This thesis analyzes and reviews the evolution and adaptation of strategies to the development stages of startup companies. A company's strategy is a goal-oriented, long-term plan that guides the decision-making process in order to achieve a competitive advantage and adapt to changing conditions. The implementation of a quality strategy is based on leveraging the company's competitive advantages, identified through strategic analyses. Based on the identified competitive advantages, a strategy and market positioning are formed. Market positioning refers to the strategic process of establishing and maintaining a distinctive place for a product relative to competitors, so that it is perceived by customers as the best option on the market. Startup companies are a relatively new form of business, characterized by innovation and rapid growth. They differ from other small businesses by their scaling potential and offer the possibility of exceptionally high returns on investment, though they are also highly risky. Their role in the economy is significant, as they bring innovations and new technologies, create new jobs, attract investments, and foster economic dynamism and competition. To be successful, startups must contain certain elements: a strong value proposition, good product-market fit, a scalable business model, an efficient team, access to financial resources, flexibility and the ability to adapt quickly, focus on customers, strategic marketing, a clear vision and mission, and innovation. As they progress through the developmental stages, startups must remain highly agile in order to adapt to challenges and survive in the market. This thesis provides a detailed description of the necessary strategies and key activities at the development stage. In addition to secondary literature, it also draws on primary sources, specifically, information gathered through an interview with the founder of a London-based startup that has been operating for four years and is currently in the growth stage.